The most ruthless file clerk in federal history

864 pages. $29.95. Never before has there been -- and probably never again will there be -- another J. Edgar Hoover.

That notion, for some, is a source of great sadness; for others, of relief.

For a greater part of the 20th century, J. Edgar Hoover was the constant grim-faced reminder of the weight and might of the federal government. That presence was part myth, part reality but all genuine power.

Curt Gentry, co-author with Vincent Bugliosi of the benchmark true-crime book "Helter Skelter," has produced an absolutely riveting account of Hoover's virtual creation of the Federal Bureau of Investigation, which he joined in 1924. It also is the tale of the use of authority and the unprecedented manipulation of power. But ultimately, it is the cautionary tale of the might of secrets -- from their often-slimy gathering to their festering growth in Hoover's oh-so-efficient files.

No one was better at amassing, swapping, trading and wielding secrets than Hoover. After all, no man, no woman is without sin, the appearance of sin or at least some discomforting personal episode. Hoover's operation was built in large measure by coercing the fallen to inform on others lest their own failings be exposed.

Despite the physical heft of "J. Edgar Hoover," it is astonishingly fast-paced. It is one of those rare serious works that you find yourself picking up -- even snatching 10 or so pages of -- whenever you have a spare moment.

Born in 1895 into a family of government employees, Hoover knew first-hand the staying power of bureaucracies. Administrations come and go, but file clerks stay forever. And Hoover became the most ruthless file clerk in federal history.

Applying the Dewey Decimal System he mastered as a Library of Congress clerk to the Department of Justice, Hoover was able to catalog a nation's human failings, complete with cross-references.

Overlaying this was his keen understanding of the mighty memo. He knew how to bury a crucial item in the mind-numbing paper avalanche he generated daily. His supposed overseers in Congress or the attorney general's office learned the hard way that they had to scrutinize each line of each memo to make sure Hoover had not included some nasty bit of business that would come back to haunt them, such as a tacit approval of wiretapping or break-ins.

Most of all, it was the relentless collection of information, gossip and intelligence that was the basis for Hoover's power. With informants and sources almost everywhere, including the Supreme Court, it seems that nearly every bit of water cooler conversation made its way into Hoover's files.

The judicious sharing of these files with the powerful was a favored double-edged Hoover maneuver. While ingratiating himself with the recipient, he also let it be known that there was a similar folder bearing the recipient's name.

Hoover's personal racism, spites and biases were fuel for the bureau's activities. The bugging of motel rooms to capture Martin Luther King's sexual romps -- and the select distribution of the tapes in hopes that King would kill himself, see his marriage ruined or repulse his supporters -- is a prime example of Hoover's perverse efforts.

Mr. Gentry, after 15 years of research, has given a road map of one man's rise to power and its ultimate corruption. One man can make a difference, and as Mr. Gentry clearly shows, it can sometimes be very frightening.